Please, please help

Hello :)
I have fairly thick, wavy hair. I wash it and straighten it with ceramic irons every third day, or so - and I use a good leave in conditioner. It feels fairly healthy to me, but perhaps that's the conditioner.

I have just made a really scary discovery. When examining for no real reason the ends of the front of my hair, (just below shoulder length, but the fronts are quite short,) I saw several 'curly' bits at the end. I've seen these before and when washed they sorta decurl. But I pulled them oh so gently just now, and they snap, just about 2 cm from the bottom. It's only a few strands but now I'm quite concerned. Could be heat damage of course, but also could be due to a botched bleach job nearly a year ago - no real damage at the time though the bleach overheated. Seems to me this problem is more or less just at the fronts, though of course I haven't properly checked the backs.

So, since I know little about hair, what does this mean? Is it just general, brittle ends, or severe damage? If the curly bits are caused by heat (eg blow drying,) are they brittle simply because of the curliness, (since when I wash again they seem to lie straight once more?) If so, will they be stronger after?

Please help, I'm rather scared!
My hair really doesn't feel that bad, that's what's so odd.